package day07;

import java.util.Random;

public class VerifcationCode {
    public static void main(String[] args) {
        //code密码
        int len=4;
        String code=generateVeriCode(len);
        System.out.println(code);
        }
    public static String generateVeriCode(int len) {//长度
        String code = "";//密码
        char[] chs = {'a','b','c','d','e','f','g','h','i','j','k',
                'l','m','n','o','p','q','r','s','t','u','v',
                'w','x','y','z',
                'A','B','C','D','E','F','G','H','I','J','K',
                'L','M','N','O','P','Q','R','S','T','U','V',
                'W','X','Y','Z',
                '0','1','2','3','4','5','6','7','8','9'};
        Random random=new Random();
        for (int i = 1; i <= len; i++) {
            int index = random.nextInt(chs.length);
            code+=chs[index];
        }
        return code;
    }}